Hello all,

Thanks for all the help over the past few months my Discovery has become part of the family. All of a sudden while driving a vibration started, it felt like a wheel became loose, but when I let off the gas the vibration stops. That couldn't be the wheel, right? So, I've checked those. Nothin loose. Any idea's guys?

Thanks,
Kelly

 

Stop driving it ASAP, check the wheel lugs first and then crawl under your truck and see if your front drive shaft has grease fittings on all 3 u-joints. If the 2 rear u-joints don't have grease fittings, it is safe to say it is failing and should not be driven. When they fail at highway speeds it results in a $7000 repair.
Get back to me and I'll walk you thru what to do.

 

Yep, Sounds like u-joints. to me... You can look at either end ofthe reardrive shaft and the front of the front shaft and easily see if that's your problem. As mike said, if they don't have grease fittings, they need to be changed anyways.

 

I am not so much concerned about the other u-joint only tje two in the constant velocity joint that hooks to the front of the t/case, they are known to fail and can make for a very expensive repair.

 

Hey Guys, I looked under the LR at the U joints. They are greased and the only thing that I noticed that looked a bit fishy was what seemed to be a bushing that had a piece missing out of it. It was kind of behind the outside parts of the u joint. Are there bushings in the unit? If so it looked like there was a chunk out of one of them. Could this be what's causing the vibration? Thanks

 

which end, of which shaft. The only place where there is any possibility of a "chunk" missing is either on the rubber boots where the driveshaft extedns, or at the rear of the rear shaft.

 

It is at the second u joint from the engine. All the joints are grease fit. Behind the U shape part of the joint it seems like a bushing, but I'm not sure. Just throwing stuff out. Thanks

 

Are you talking about the rubber seal on the end of each arm of the u-joint cups? If so, it has failed. You never answered my first question, do the 2 u-joints in the constant velocity joint, where it hooks to the t/case, have grease fittings?

 

Mike, yes it does have greese fittings. I was looking at the shop manual and picked up some part lingo. The bushing i was referring to is one of the four arms that are on the spider in the middle u joint. The front drive shaft looks pretty easy to take off. Should I take this off and inspect closer? If the problem could be the need of a new spider or bearings in the joint that seems easy enough to fix.

 

Are you referring o the centering ball kit, if it is get loose and sloppy, that will surely cause some shaking.